1. Field of the Invention
This invention relates generally to telephonic voice communication and switching, and in particular to a multi-channel telephone data collection, collaboration and conferencing system and method.
2. Description of the Related Art
Numerous techniques, ranging from the simple to the complex, exist to perform telephone conference calls. A simple three party analog conference call is frequently implemented by adding the third party across an existing two party circuit, while complex conference calls are implemented using a digital voice transmission and switching system.
Common conference calls can be either analog or digital in nature and the techniques to perform the conference call follow either an additive approach or switched approach. In the additive approach, each conference participant receives the algebraic sum of the signals of the other conference participants. In the switched approach, an attempt is made to discover which conference participants are the speakers, and those speaker""s signals are then sent to the other conference participants. Typically, analog conference techniques follow the additive approach, while digital conference techniques may follow either the additive or the switched approach.
In the digital environment, additive techniques suffer from several difficulties. First, the range of amplitude levels of the signals must conform to set minimum and maximum values in order to be transmitted. While each conference participant""s signal may stay within the acceptable bounds, the sum of all of the conference participants may not. Another difficulty with the additive method is the presence of not only the speaker""s signals but also the combined idle channel noise of all of the silent conference participants.
For these reasons, the switched approach has most often been proposed for digital conferencing circuits, but the known prior art has several deficiencies.
U.S. Pat. No. 3,674,936 to Wolfe discloses a voice conferencing system. The system gives a modular data processing system the facility for providing virtual cut through (xe2x80x9cVCTxe2x80x9d) service that allows the transmission of continuous traffic as well as digital voice communications. The term virtual cut through refers to the ability of the system to receive the message and pass it through the system for transmission practically simultaneously. That is, it is accomplished as if the incoming circuit were actually switched to the outgoing circuit as is done in a circuit switching system. The system accomplishes the virtual cut through without circuit switching by providing a path through the system between input and output lines virtually directly. It is done without any inspection of the incoming data whatsoever. The data may or may not be encrypted to provide a means for secure communication. In order to prevent superposition of the incoming voices, a priority scheme is used wherein each participant automatically excludes those xe2x80x9cbelowxe2x80x9d him while he is talking. The assignment of the priority of each conference participant is made by the originator of the conference call when setting up the call (See Wolfe, column 3, lines 10-15). The Wolfe reference does not disclose the ability to schedule the playback of the telephone conference call participants according to a programmable talk mode nor the ability to use speech recognition as a controlling means.
U.S. Pat. No. 3,958,084 to Nicholas discloses a conferencing apparatus. The apparatus selects a conference participant if the speaker""s signal has exceeded a predetermined reference level. The reference level is continuously allowed to decay so that new speakers may gain the floor when the current speaker""s peak signal falls below the peak signal of another speaker. In addition, the Nicholas reference directs the incoming signals of the conference participants to all of the other conference participants. The Nicholas reference does not disclose the ability to schedule the playback of the incoming signals nor does it disclose the use of speech recognition to control the operation of the system.
U.S. Pat. No. 5,916,302 to Dunn et al. discloses a multimedia conferencing system using parallel networks and is owned by the assignee of the present invention. The Dunn reference discloses a conference server system for internal use in the public switched telephone network (PSTN) for distributing computer displayable data between participants in voice telephone conferences. A speech recognition apparatus within the PSTN may be linked to a conference bridge for recognizing voice commands of conference participants and enabling either management of the system or the data network to perform actions associated with such commands (See Dunn, column 9, lines 22-29). The Dunn reference does not disclose control over the sequencing of audio playback, the use of text to speech synthesis by the controller, or the ability to transcribe the separate channels of the conference call.
U.S. Pat. No. 5,771,273 to McAllister et al. discloses a network accessed personal secretary. The McAllister reference is accessible by a subscriber whenever the subscriber""s telephone is in an off-hook state. Speech recognition means are placed to monitor the subscriber line and be responsive to a pre-selected utterance that generates a signal to access the platform. The signal generated by the speech recognition means is received at a central office switch and is associated with the subscriber line. The generated signal acts as a xe2x80x9cwake-upxe2x80x9d signal for bridging the subscriber line with the service platform. When the subscriber is connected to the platform, the platform is activated to perform functions for the subscriber such as relaying voice and fax messages, maintaining a calendar and event scheduler that is reviewed on request, setting up conference calls, and dialing calls to specific destinations (See McAllister, column 3, lines 50-54). The McAllister reference does not disclose the ability to schedule or sequence the incoming signals of the conference participants nor the ability to share information about the status and nature of other callers in the system using parallel speech recognition.
U.S. Pat. No. 4,908,866 to Goldwasser et al. discloses a speech transcribing system. The device enables transcription of spoken speech wherein periods of silence are deleted without interfering with the reproduction function. The reference records the spoken word and stores the spoken words in a memory. A typist can then listen to the recorded spoken word and transcribe the speech as if he or she was hearing them directly from the speaker""s mouth. Since most typists cannot normally keep up with dictation, the typist may change the time delay through the memory buffer from zero to some number of seconds. The Goldwasser reference does not disclose the ability to directly transcribe spoken speech to text using a speech recognition system nor the ability to control the behavior of the transcription capabilities via either voice command or DTMF commands.
Therefore, there remains a need for a telephone conferencing system which permits the user to define several programmable talk modes with which to schedule playback of the input signals received from each conference participant. In addition there remains a need for the automatic speech to text transcription capability for each incoming channel, and the use of speech recognition to set up and control the operations of the conference call.
It is therefore an object of the present invention to provide a multi-channel telephone data collection, collaboration and conferencing system and method that permits the conference participants to schedule the playback of incoming signals according to a programmable talk mode.
It is an additional object of the present invention to provide a multi-channel telephone data collection, collaboration and conferencing system and method that provides automatic channel by channel transcriptions during a conference call.
It is also an object of the present invention to provide a multi-channel telephone data collection, collaboration and conferencing system and method that uses text to speech synthesis to announce pertinent data and the addition or deletion of conference participants to all conference participants during the conference call.
It is yet another object of the present invention to provide a multi-channel telephone data collection, collaboration and conferencing system and method that can be used to train a speech recognition application to recognize spoken words over several different channels.
To achieve these and other objects and features of the present invention, there is provided a multi-channel telephone data collection, collaboration and conferencing system. The multi-channel telephone data collection, collaboration and conferencing system for use with a plurality of telephone channels interconnected to facilitate a conference call between a plurality of conferencing devices comprises a call processor having at least two conferencing device input/output ports connected to the processor and to the plurality of conferencing devices. The call processor generates an audio signal corresponding to each of the plurality of conferencing devices connected to the input/output ports. An audio saving module, connected to the call processor, converts the audio signal corresponding to each of the plurality of conferencing devices to a digital signal. A memory device stores the digital signals corresponding to each conference device and an audio switch, connected to the call processor and the memory device has a plurality of audio inputs corresponding to each of the conference devices. An application logic controller is connected to the call processor, the audio switch and to the memory device and controls the operation of the system and generates a select signal according to a programmable talk mode, the select signal selects at least one of the audio switch inputs to present to the output ports of the call processor.
The system operates to allow any of the following actions to be implemented during a conference call: add predetermined conferencing devices to the conference call; add new conferencing devices to the conference call on an ad hoc basis; selectively remove (disconnect) conferencing devices from the conference call; permit the conference call to be sub-divided into a plurality of sub-conference calls between subgroups of the plurality of conferencing devices; and block portions of the conference call relative to a subset of its current conferencing devices.
The teleconferencing method for use with a plurality of telephone channels interconnected to facilitate a conference call between a plurality of conferencing devices comprises the steps of receiving an audio input signal corresponding to each of the plurality of conferencing devices; storing the audio input signal in a memory device; retrieving at least one audio input signal stored in the memory device in accordance with a programmable talk mode; and outputting the at least one audio input signal to the plurality of conferencing devices.